The document provides information about lasers used in dermatology. It discusses the basics of lasers including their components and principles. It describes different types of lasers such as CO2, Er:YAG, pulsed dye, Nd:YAG lasers and their wavelengths. It outlines the uses of lasers in treating conditions like vascular and pigmented lesions, hair removal, tattoos and various skin disorders. It also discusses laser safety and potential side effects.

1. BASICS OF
LASER

2. “LASER”isanacronym that stands for Light
Amplification by the Stimulated Emission of
Radiation.
Laser is an instrument that generates a beam of light of a
single wavelength or color that is both highly collimated
and coherent.
DEFINATION

3. Principle of Laser

4. BASICS COMPONENTS OF LASER

5. • The first functional laser (ruby, 694 nm) was
developed by Maiman in 1960.
HISTORY

6. Monochromatic: composed of a single wavelength or color.
Coherence: All the waves of light move together temporally and
spatially.
Collimation: where the transmission of light occurs in parallel
fashion without significant divergence, even over long distances.
Characteristics of Laser light

7. Electromagnetic Spectrum :

8. 1. Argon Laser: 488/514 nm
2. Potassium-titanyl-phosphate (KTP): 532 nm
3. Copper bromide/vapour: 510/578 nm
4. Argon-pumped tunable dye (APTD): 577/585 nm
5. Krypton: 568 nm
6. Pulsed dye laser (PDL): 585/595 nm
7. QS ruby: (694 nm)
8. QS alexandrite: (755 nm)
9. QS neodymium (Nd):yttrium-aluminum-garnet
(YAG): 1064 nm
10.Erbium:YAG: 2940 nm 11.Carbon
dioxide Laser: 10,600 nm
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Lasers Commonly Used in Dermatology

10. Power: The rate at which energy is emitted from a laser. Watts.
Joule (J): A unit of energy used to describe the rateof energy
delivery.
Fluence: determines the amount of laser energy per unit area
and is expressed in joules/cm2.
Spot Size: The mathematical measurement of the radius of the
laser beam.
Terminology

11. Pulse: A discontinuous burst of laser as opposed to a continuous
beam.
Pulse Frequency: The rate at which pulses are generated. Is
expressed in pulses per second (Hz).
Pulse Duration: The "on" time of a pulsed laser. Measured in
terms of ms, μs, or ns.

12. Irradiance: (power density) The rate at which energy is delivered
per unit area.
It determines the ability of a laser to incise, vaporize, or
coagulate tissue and is expressed in watts/cm2.

13. Thermal Relaxation Time(TRT): time required for the
dissipation of 63% heat gained by the tissues (ms/μs) during
irradiation.
Thermal Damage Time(TDT): The time for the entire target
including the primary chromophore and surrounding target to cool
by 63%.
Focus: The exact point at which the laser energy is at peak power
63
%

14. Are the selectively laser energy absorbing target molecules in
the skin.
1. Endogenous chromophores:
• Melanin: UV -1200nm
• Hb: UVA, blue (400 nm), green (541 nm), Yellow (577nm)
• Collagen: Visible and near infra-red spectra
• Water: in the mid and far infrared regions
2. Exogenous chromophores: Such as tattoo ink.
Chromophores in the Skin

15. Laser are classified according to the nature of the amplifying
medium: gas, liquid(dye) or solid state:
Classification of Lasers

16. • Continuous wave
• Quasi CW
• Pulsed
Modes of Output

17. ABLATIVE: outer layers of skin are (removed) through
vaporization of the cells. Healing takes place by re-deposition of
collagen.
Egs:
Er: YAG
CO2 laser
NON-ABLATIVE: induce dermal neocollagenesis without
epidermal disruption,
KTP
Pulsed Dye
Nd: YAG
Ablative Vs Non Ablative

19. Laserbeam is “fractionated” into apattern where someparts of the
skin are targeted, and the other parts are left intact. A grid like
pattern appears on the skin.
FRACTIONATED LASER

20. How Fractionated Lasers Work

21. Tissue Optics

22. 1. Reflection.
• 4–6% of light is reflected.
• Lowest when the beam is perpendicular.
2. Absorption. Depends on the properties
of the substance through which the light
passes.
Target molecules are called chromophores:
(1) Melanin
(2) Hemoglobin
(3) Water
(4) Collagen
Tissue Optics :

23. 3.Scattering. Is the deviation of light by non-
uniformities in the medium
Eg: collagen in the dermis.
It reduces the energy available for the
target chromophores.
4.Transmission. Light that is not
Reflected, absorbed or scattered
passes to deeper tissue.

24. 1) Photostimulation:Low expedite wound energy lasers
healing.
Light-Tissue Interaction

25. 2. Photodynamic change: uses topical or systemic
photosensitizers. Subsequent irradiation elicits a photo-
oxidative reaction and an immediate cytotoxic effect.

26. 3) Photo-thermolytic and Photo-mechanical Effect: works on
the principal of Selective photothermolysis: A concept used to
target chromophore based:
• on its absorption characteristics,
• the wavelength of light used,
• amount of energy delivered.
• the duration of the pulse,

27. 4.Photo Acoustic Effect

28. Uses of Laser: Lasers
1. Hair Reduction:
Chromophore: Melanin
Long pulsed Nd:Yag
(1064nm)
Alexandrite laser (755nm)
2.
Hyperpigmentation:
Chromophore: Melanin
(a) Epidermal Type Q switched, Nd:Yag
(532nm)
PDL
(b) Dermal Type: Q switched Nd:Yag
Uses of Lasers:

29. 3. Vascular Lesions:
Chromophore: Hemoglobin
(a) Port wine stain PDL
Alexandrite laser (755nm)
Q switched Nd:Yag
(1064nm)
(b)Small calibre
Telengiectasia
PDL
(c) Large Vessel
Telengiectasia
Krypton Laser (568nm)
Copper vapour Laser

30. (4) Facial
Rejuvenation:
(a)
Ablative:
CO2
laser(10,600nm)
Erb:Yag laser (2940nm)
(b) Non-Ablative:
PDL
Q-switch Nd:Yag
(1064,532)
(5) Hypertrophic scars, warts,
PD
L benign neoplasm
(7)
Acne
PD
L
(6)
Hemostasis
CO2 Laser
(10600nm)
(7) Laser
Lipolysis:
Nd: Yag Laser
(1064nm)
Chromophore:
Water

31. (8)
Tattoos:
(b) Green
(c) Red/ Orange/ Purple
Q-switched ruby,
Q-switched alexandrite
Q-switched 1064-nm Nd:YAG
Q-switched ruby,
Q-switched alexandrite
Q-switched Nd:YAG 532-nm
Chromophore: Tattoo Ink
(a) Blue/ Black

32. Cooling Systems

33. Contact skin cooling
• Active
Copper, or sapphire tips:
For delivering longer pulse durations(>10 ms)
Provide pre, parallel and post laser cooling.
• Passive
Ice cubes:
Reduces inflammation post procedure.
Easy method.
Disadvantages: a waiting period
Melting water on the skin
Aqueous gels:
Not advised nowadays.
Cannot provide prolonged cooling.
Cooling Systems

34. 1) Cryogen spray (liquid nitrogen):
(a) Not recommended now causes
cryonecrosis.
2) Pulsed cryogen spray (dynamic cooling
device):
(a) Provides uniform cooling at -30C
(b) Method of choice
3) Forced refrigerated air:
(a)Delivers chilled air pre, parallel and
post procedure.
(b) By convection cooling.
Non Contact Cooling:

35. Preparing A Patient for
Laser Session:

36. 1. Take History to find out:
• Immunocompromised status, esp diabetes
• Isotretinoin use.
• Active local or systemic infections especially recurring HS
infection. (Aciclovir or valaciclovir given 1 day prior to &
5–14 days post treatment)
• Tendencyto keloid scarring.
• Personal or family historyvitiligo.
2. Prophylactic antibiotics and antivirals for ablative procedure
3. To minimize post laser hyperpigmentation: 2 weeks
before and 8 weeks after laser:
0.2% Retinoid preparation
2% Hydrocortisone
4% Hyroxyquinone
Anesthesia:
Topical anesthetic ointment under occlusion for 1 hr.
Patient Selection

37. Absolute:
• Active bacterial,viral or fungal infections
• Unrealistic expectations
• Uncooperative pts
• Malignancy
Relative:
• Immunocompromised: Diabetes, HIV, Hepatitis B,C
• Oral isotretinoin
• Fitzpatrick skin 5-6 phototypes
• History of keloids.
• Patients taking gold salts are at the risk of chrysiasis (gold-
related skin discoloration).
Contraindications:

38. Precautions:

39. • Laser room should be properly labeled.
• Hang eye goggles on the door.
• Unauthorized people should not be allowed.
• The room should not contain volatile substances such as
ether, alcohol .
• Plume evacuator: for larger lesions and warts.
Precautions:
The Operating Room:

40. • Special glasses should be used.
• Patient Consent
• The surgeon should use the special glasses for the
particular laser.
• NEVER look directly into the laser source.
• NEVER point the hand probe in any direction, except
towards the area to be treated.
Safety measures for the Patient:
General measures:

41. • Do not rub, scratch or put pressure on the treated area
• Do not apply make-up in case of severe reaction.
• Avoid sunlight; Sun blocks can be advised.
• Ice bags to alleviate erythema and edema.
• Emollients to keep skin moist.
• Avoid irritants to the resurfaced areas
• Erythema and edema settle with topical corticosteroids
SKIN CARE INSTRUCTIONS AFTER
LASER SURGERY:

42. SIDE EFFECT OF LASERS:

43. (1) Immediate:
• Pain, burning sensation, edema
(2) Early:
• Oozing, crusting
• Secondary infection
• Reactivation of HS infection
Side Effects of Lasers:

44. (3) Late:
• Dyspigmentation (hypo/hyper)
• Change in skin texture
• Demarcation lines
(in facial rejuvenation)
• Keloids and hypertrophic scars
• Scarring
• Milia
• Persistent erythema
• Dilated follicular ostia

45. Nd:YAG (neodymium-doped yttrium aluminum garnet) is used as a
laser medium.
• Wavelengths: 532nm and 1064 nm,
• Penetrates 2-3mm into dermis
QSNd:YL 1064-nm:
Has the least absorption by melanin
Deepest penetration.
Effective for both epidermal and dermal pigmented lesions.
QSNd:YL 532-nm:
Is well absorbed by both melanin and hemoglobin.
Has superficial penetration,
Limited to treating epidermal pigmented lesions.
Nd:Yag Laser:

46. Spider and thread veins
Varicose veins Telangiectasia
Haemangioma
Solar lentigines
Freckles
Nevus of Ota and Ito
Mongolian spot
Café-au-lait-macules.
Vascular Lesions:
Pigmented Lesions:

47. Hair Removal:
Tattoos:

48. • Contains a rhodamine dye
• Wavelength: 585–600 nm.
• Pulse duration:0.45 ms (short-pulse)
1.5–40 ms (long-pulse PDL)
• Penetrates the dermis to a depth of 1.2 mm &
photocoagulates vessels of up to 100 μm in diameter.
• Primary chromophore: hemoglobin.
Pulsed Dye Laser:

49. • Port wine stains
• Superficial hemangioma
• Telangiectasia
• Plane warts
• Pyogenic granuloma.
• Melasma
• Hypertrophic scars
• Nail psoriasis/plaque psoriasis
USES:
Cutaneous Vascular
Lesions:
Non-Vascular Skin conditions:

50. Active laser medium: 10–
20% carbon dioxide,
Exists as Ablative nonfractinated laser
Ablative fractinated laser
Wavelength: 10,600 nm
Primary chromophore: Water
Carbon Dioxide Lasers:

51. • Depth: 20-30 µm of skin (epidermis and superficial
papillary dermis)
• In the healing period: re-epithelialization

52. The following skin disorders can be treated with carbon
dioxide laser beams:
• Rhytides
• Acne scars
• Varicella and smallpox scars
• Verruca vulgaris/plana
• Junctional & compound Nevi
• Small syringomas

53. THANK YOU